Heretofore, as shown in FIG. 44, a disc cartridge 101, such as a DVR, DVD, DVD-ROM and the like, has been constituted such that it rotatably houses a disc D between upper and lower shells 102 and 103, and a pair of upper and lower pick-up insertion slots 104 are opened and closed from the upper side of the upper and lower shells 102 and 103 by a substantially U-shaped shutter 105, and the shutter 105 is slid along one side surface 101a of the disc cartridge 101.
However, in such a conventional disc cartridge 101, there has been a problem in that, because the shutter 105 is attached outside, this shutter can be so easily slid and opened that the disc D housed inside may become damaged or dust and the like may adhere to the disc D, thereby making dropouts likely during writing and/or recording of a data.
The present invention has been made in order to solve the above-described problem, and an object of the invention is to provide a disc drive unit in which opening and closing driving of the shutter by rotation of an inner rotor in the disc cartridge can be simply performed, the pick-up insertion slot being opened and closed by means of the shutter, from the inside by rotation of the inner rotor in which a disc-shaped recording medium is housed so that the shutter is not easily opened from the outside.